Method of molding and assembling



Aug. 22, 1967 G. RRYAN METHOD OF MOLDING AND ASSEMBLING 5 Sheets-Sheet 1 Original Filed Oct. 8, 1959 Inventor George RXRg n.

G. R. RYAN METHOD OF MOLDING AND ASSEMBLING Aug. 22, 1967 5 Sheets-Sheet 2 Original Filed Oct. 8. 1959 Inventor George R. 122cm.

Aug. 22, 1967 G. R. RYAN 3,336,654

METHOD OF MOLDING AND ASSEMBLING Original Filed Oct. 8, 1959 5 Sheets-Sheet 3 zoo 9i 9o 6! no 95 Inventor Ge rge R. R nn.

Aug. 22, 1967 R, RYAN 3,336,654

METHODOF MOLDING AND ASSEMBLING Original Filed Oct. 8, 1959 5 Sheets-Sheet 4 3 r 13 3o' 15 I 31 29 29' 6 40 so 5 /1 W MW l Inventor I George R Ran m G. R. RY AN METHOD OF MOLDING AND ASSEMBLING 5 Sheets-Sheet 5 Original Filed Oct. 8, 1959 Inventor George 12. Rana United States Patent 3,336,654 METHOD OF MOLDING AND ASSEMBLING George R. Ryan, Wankegan, 11]., assignor, by mesne assignments, to Brunswick Corporation, Chicago, 11]., a corporation of Delaware Original application Oct. 8, 1959, Ser. No. 845,127, now Patent No. 3,135,993, dated June 3, 1964. Divided and this application June 8, 1964, Ser. No. 373,442

4 Claims. (Cl. 29--429) This application is a division of application Ser. No. 845,127, filed Oct. 8, 1959, now Patent No. 3,135,993.

The present invention relates generally to improved ways of molding and assemblying plastic materials and parts. More particularly, the present invention relates to improved methods of automatically molding a thermoplastic material about a mold core element, such as a hypodermic needle cannula.

Hypodermic needles have for many years been manufactured with screw machine fabricated metal hubs. Many attempts have been made to replace these metal hubs with hubs made from more economical materials and by less expensive methods of manufacture. In one prior attempt to produce economically a molded plastic hub on a hypodermic needle cannula, the needle cannulae were loaded into mold cavities by hand or with the aid of a loading jig or fixture. Frequently in this operation, however, the points of the cannulae were damaged and considerable time and money were expended in inspecting and resharpening the needle points damaged during the several manipulative steps. Also, each of the molded hubs thus produced had to be placed in a suitable container or provided with a suitable protective sheath which further added to the overall cost of producing the needle. As all other known processes and apparatus for producing molded plastic hypodermic needle hubs are no more suitable for the large scale commercial production of plastic hypodermic needle hubs than the above described process, there has to date been no eflicient and reliable method and apparatus for molding a plastic hub on a hypodermic needle cannula.

It is therefore an object of the present invention to provide new and improved method of molding plastic material.

It is a further object of the present invention to provide an improved method of automatically and continuously molding plastic materials.

Another object of the present invention is to provide an improved method of molding a plastic material about a preformed member.

Still another object of the present invention is to provide an improved method of molding a plastic material about a preformed member which is mounted on a mold core element secured to a continuous conveyor.

A further object of the present invention is to provide an improved method of molding a plastic material about a hypodermic needle cannula to provide a hub therefor.

Still another object of the present invention is to provide an improved method of molding a plastic material about a molded plastic part while the said part remains mounted on its mold core element or other element supported on said mold core element.

Another object of the present invention is to provide an improved method of automatically molding a plastic composition hub on a hypodermic needle cannula and simultaneously molding a plastic composition sheath for the said cannula.

A further object of the present invention is to provide an improved method of assembling a protective sheath on a hypodermic needle hub.

It is also an object of the present invention to provide an improved method of assembling a preformed part with 3,336,654 Patented Aug. 22, 1967 a molded structure while said structure is mounted on its mold core element.

A still further object of the present invention is to provide an improved method of printing, marking, or otherwise operating upon a molded article while the said molded article remains mounted on a mold core element therefor.

Other objects of the present invention will be apparent to one skilled in the art from the detailed description and claims to follow in conjunction with the accompanying drawing wherein:

FIGURE 1 is a fragmentary perspective view of the molding and assembling aparatus of the present invention viewed from the front thereof;

FIGURE 2 is a perspective view of the molding and assembling apparatus of FIG. 1 viewed from the rear end thereof;

FIGURE 3 is a top plan view of the molding and assembling apparatus of FIG. 1 taken along the line 33 of FIG. 2;

FIGURE 3A is a fragmentary vertical sectional view of FIGURE 3;

FIGURE 4 is an enlarged fragmentary perspective view of the cannula loading wheel shown in FIG. 1;

FIGURE 5 is a fragmentary side elevation view of the cannula loading wheel of FIG. 4;

FIGURE 6 is a vertical sectional view of the apparatus taken along the line 6-6 of FIG. 5;

FIGURE 7 is a vertical sectional view of the apparatus taken along the line 7-7 of FIG. 3;

FIGURE 8 is a schematic view of the drive means for theconveyor means of the apparatus of FIG. 1;

FIGURE 9 is a fragmentary vertical sectional view along the line 9-9 of FIG. 3;

FIGURE 9A is a vertical sectional view of the chain centering bars of FIGURE 9 in closed engagement with the link chain conveyor shown therein;

FIGURE 10 is an enlarged fragmentary vertical sectional view of the sheath mold means and associated element of FIG. 9 with the mold means in closed position;

FIGURE 11 is an enlarged fragmentary vertical sectional view partially in side elevational view of the hub molding means of FIG. 9 with the mold in closed position;

FIGURE 12 is a fragmentary side elevational view of the hub molding means of FIG. 11;

FIGURE 12a is a fregmentary side elevational view of the hub molding manifold cap of FIG. 9;

FIGURE 12b is a fragmentary top plan view of the hub molding manifold cap of FIG. 9; and

FIGURE 13 is a fragmentary plan view of the hub mode core chain and the sheath mold core chain schematically showing the assembling procedure.

Referring to the accompanying drawing, there is shown an apparatus for molding a thermoplastic compound, such as methamethacrylate or polyethylene plastic, about a mold insert element comprising a hypodermic cannula I mounted on a hub mold core element 5 to form a hub 60 and simultaneously molding a hypodermic needle protective sheath 61 which is detachably mounted on the hub 60. In the hub molding apparatus of the present invention a plurality of the cannulae 1 are positioned in a hopper 2 with the pointed end of each cannula 1 extending outwardly and lying in a plane parallel to the plane of the hub core element 5 which preferably forms an integral extension of the pivotal link pin 6' of the link chain wherein the individual links are spaced by conventional sprocket locked in position by chain groove 10 in the periphery thereof to receive therein a cannula 1 from the hopper 2 as the wheel 4 moves past the lower end of the hopper 2. The grooves 10 are spaced circumferentially on the wheel 4 a distance equal to the distance between the mold core elements on the chain 6. The grooves are adapted to receive therein the outer end of the mold core element 5 which is made in the form of a small diameter gradually tapered spike 7 having a pointed end and adapted to fit into the bore of the cannula 1. The grooves 10 lie in a plane parallel with the plane of the axis of the hub core element 5 and are positioned opposite a hub core element 5 during one portion of the rotation of the loading wheel 4.

As the loading wheel 4 is continuously rotated in a clockwise direction by means of the drive sprocket 3' which is rotatably driven by the drive chain 3, the cannulae 1 in the grooves 10 successively pass below the friction cannula loader 9 which engage the cannula 1 extending across the channel 9 in the loading wheel 4 to slide the cannula 1 onto the spike 7 of the mold core element 5. The cannula 1 thus is mounted on the hub core element 5 and is carried to the hub molding station by the intermittent movement of the endless chain 6.

As the endless chain 6 advances the hub mold core element 5 with each supporting a cannula 1 to the hub molding station while he mold is in the open position, the chain 6 comes to rest on the lower chain centering bar 28 (see FIG. 9) which is resiliently supported by spring means 30 on the lower mold block secured to the mold base 12. The spring means 30 normally holds the mold core element 5 in a position slightly above the mold cavities so that the mold core elements 5 and the molded hubs 60 are clear of the surface of the mold sections and can be moved thereacross without contacting the mold surfaces. In order to insure the proper alignment of the chain 6 on the bar 28 it is desirable that the chain 6 be guided toward the molding means by an upper chain guide bar 66 centering the chain generally with the aid of the oppositely disposed lower chain guide bar 66. The lower chain centering bar 28 positions the mold core elements 5 above the hub mold cavities of the lower hub mold section 24 in the hub mold assembly. As soon as the mold core elements 5 are positioned above the mold cavities of the lower hub mold section 24, the upper mold assembly is moved slowly downwardly under low hydraulic pressure. The upper chain centering bar 29 extending the length of the mold is resiliently mounted on the upper mold assembly by spring means 30' and has a plurality of sprocket-like teeth 29 extending downwardly and engageable with the link chain 6. The pressure applied by the downwardly moving centering bar 29 depresses the hub core element 5 into the mold cavities and more accurately centers the hub mold core elements 5 in the mold cavities. While the chain 6 which carries the mold core elements 5 is held between the centering bars 28, 29 and with the surfaces of the lower mold section 24 and the upper mold section 25 within a few thousandths of an inch of each other, the hydraulic mechanism applies high pressure to the movable upper mold section 25 in order to bring the fixed lower hub mold core centering section 26 and the fixed upper hub mold core centering section 27 on the lower and upper mold sections, respectively, into engagement with the shank portions 5 of the mold core elements 5 and the centering disc 40 of the mold core element 5, thereby forcing the said mold core elements 5 very accurately into molding position within the mold cavity and holding the mold sections in molding engagement during the entire injection molding operation. When thus arranged and positioned, the cannula 1 mounted on the mold core element 5 extends outwardly from the mold cavity with the outer end thereof disposed in the groove 58 in the lower hub mold manifold cap 18. The upper hub mold section 25 mounted on the movable upper platen 13 is actuated by a hydraulic piston 75 and is maintained in proper alignment at all times with the lower mold assembly by platen guide rods which are fixedly disposed in the fixed platen 11 of the molding apparatus supported by the frame In the hub molding cycle the lower mold 24 and the upper mold are maintained at their proper temperature for molding by means of heating or cooling fluids being circulated through fluid passages 31, 31', in the respective mold blocks. The heating elements 33, 33' in the lower hub mold manifold 16 and the upper hub mold manifold 17, respectively, maintain the proper temperature of the plastic in the manifolds, the said temperature in the manifolds being controlled by the thermostats 34,

The upper surface of the lower hub mold manifold 16 has mounted thereon a manifold cap 18 which has a small diameter passage 56 extending therethrough communicating with the plastic gate 22 in the end plate 19 attached to the lateral surface of the lower hub mold section 24. With the mold core elements 5 positioned within the mold with the sections in molding engagement, the hydraulic piston 74 activated by the timing cam means 134 forces the viscous plastic from the heated chamber 72 through the several passages 32, 32', and 56 and injects the plastic through gates 22 into the several hub mold cavities formed by mold sections 24, 25. The temperatures within the mold sections and manifolds and the pressures in the hydraulic system are indicated on the control panel 81.

After the plastic is injected into the mold cavities, the mold sections 24, 25 are kept in closed position for several seconds until the plastic has set into a rigid structure. The movable platen 13 is then elevated by hydraulic piston 75 which is activated by the timing cam means 134. The spring means lifts the bar 28 and raises the chain 6 supporting the hub inserts 5 and the molded hubs 60 above the surface of the mold section 24. The Geneva gear drive means 138 then intermittently advances the chain 6 carrying the molded hubs 60 longitudinally a sufficient distance to remove the hubs 60 from the mold sections and to advance another set of hub mold core elements 5 mounted on the chain 6 between the mold sections 24, 25 and the molding process is repeated. Thereafter, the hubs 60 remaining mounted on the hub mold core elements 5 are advanced to the assembly station where a sheath 61 is mounted on each hub 60, after which the needle hub and sheath assembly is stripped from the hub mold core elements 5 and packaged, as will be described in detail hereafter.

The hypodermic needle cannulae covers or sheaths 61 are preferably molded simultaneously with and on a molding apparatus adjacent to the hub molding apparatus just described. Since there is no metal part or mold insert, such as a cannula, associated with the sheath 61, there is no need for using a loading hopper 2 or a loading wheel 4 in the sheath molding apparatus. Accordingly, an endless link chain 63 spaced laterally of the chain 6 and moving in a plane parallel to that in which the chain 6 travels, is supported at one end of the apparatus by an idling sprocket wheel 142 and at the other end of the sheath molding apparatus by a power driven sprocket Wheel 143 operated intermittently by the Geneva gear drive means 138. The chain 63 has a plurality of sheath mold core elements 62, each preferably being an integral extension of the pivotal link pins of each of the links of the endless link chain conveyor 63. As the chain 63 intermittently advances the sheath mold core elements 62 to the sheath molding station, the chain 63 comes to rest on the lower chain centering bar which is resiliently supported by spring means 49. The spring means 49 normally holds the sheath mold inserts 62 in a position slightly elevated above the surface of the mold cavities so that the core elements 62 and the molded sheath formed thereon are clear of the mold cavities and can be moved thereacross without contacting the lower mold section 43. The lower sheath mold section 43 which is supported on the mold base plate and preferably has the same number of cavities as the hub mold section 24.

The upper sheath mold section 44 is attached to the upper mold base plate 35" which is mounted on the movable upper platen 13 is moved downwardly toward the lower mold section 43 under low hydraulic pressure from the hydraulic pressure piston 75. The upper chain centering bar 46 resiliently supported by spring means 50- has a section of sprocket-like teeth 46 extending downwardly from the upper mold section 44 along the length thereof which engages the link chain 63 and generally centers the sheath mold core elements 62 in the sheath mold section 43. When the upper and lower mold sections 43, 44, respectively, are within a few thousandths of an inch of each other, the hydraulic mechanism applies high pressure to the movable upper mold section 44 to bring the lower mold core elements centering section 47 and the upper mold core element centering section 48, each fixedly mounted on the lower and upper mold sections 43, 44, respectively, into engagement with the shank portion 51 of the core elements 62 and the centering disc 52 formed thereon, thereby forcing the sheath core element 6-2 accurately into mold position with in the cavities of the sheath mold formed by the lower and upper mold sections 43, 44, respectively and holding the mold sections in molding engagement during the molding operation.

The lower sheath mold section and the upper sheath mold section 44 are maintained at their proper temperatures for molding by means of heating or cooling fluids circulating through fluid passages 41, 41'. The lower sheath mold manifold 37 and the upper sheath mold manifold 38, respectively, are heated by heating elements 55, 55, respectively, which are controlled by thermostats 54, 54. The plastic material is conveyed to the sheath mold cavities from a heated plastic reservoir 72 by means of conduit 53 communicating with passage 57 in the lower sheath manifold 37 which connects the plastic gate 42 in the lower sheath mold section 43 and through the sheath manifold cap 40.

When the sheath mold core elements 62 are accurately positioned with the mold completely closed in molding engagement, the hydraulic piston 74' forces plastic from the plastic reservoir 72 into the several sheath mold cavities through gate 42. After the plastic is injected, the mold sections 43, 44 are held in molding engagement until the plastic has set. The upper sheath mold 44 is then elevated by the hydraulic piston 75. The spring means 49 then raises the chain 63 along with the sheath mold core elements 62 and the molded sheaths 61 formed thereon so that the sheaths 61 clear the lower sheath mold section 43. The Geneva gear drive means 138 then advances the chain 63 and the molded sheaths a sufiicient distance to remove all the sheaths from the mold and to present another set of sheath mold core elements 62 to the molding station, whereupon the sheath molding cycle is repeated.

Following the hub and .sheath molding operations, the molded hubs and the molded sheaths 61, each mounted on their respective mold core elements, are advanced simultaneously toward the assembly station 90, as the Geneva drive means 138 advances simultaneously both endless chains 6 and 63, respectively. The sheath mold core chain 63 moving in a path parallel to the path of the hub mold chain 6 is engaged between the lower and upper chain guide bars 96, 96', respectively, and holds the chain 63 so as to prevent both lateral and vertical movement thereof. While thus held, the lower and upper sheath stripping bars 91, 91 respectively, engage the vertical end surfaces of the sheaths 61 and forces the molded sheaths 61 off the mold core elements 62, as the hydraulic piston 95 moves the stripper bars 91, 91' away from chain 63. The sheaths 61 fall into a sheath receiving compartment 98 whichis divided into a plurality of individual sheath compartments 99 by a plurality of dividers 100. The compartment 98 is provided with a floor member 101 pivotally mounted at its outer end 111 and having a plurality of longitudinally extending grooves 102 On the upper surface thereof into which the sheaths fall when they are ejected from the sheath mold core elements 62. The rear wall of each sheath compartments 99 has as opening therein for the passage of a sheath pusher rod 103 which rides in groove 102. The rod 103 is actuated by a hydraulic piston 105. On the lower side of the floor member 101 is mounted a cam surface 107. A cam rod 108 with a roller 108' on the end thereof is mounted for reciprocable movement below the fioor 101 for engagement with the cam surface 107 and is reciprocably moved by the piston 105. The cam rod 108 and the sheath pusher rod 103 move forwardly simultaneously as the piston 105 moves forwardly. As the cam rod 108 advances, the floor member 101 is moved upwardly until the grooves 102 hubs mounted on the mold core elements 5. The pusher rod 103, when it is fully advanced, positions the sheath 61 which is lying in the groove 102 of the compartment on the hub 60 which remains on the hub mold core element 5 where it is retained frictionally.

After the sheath 61 is assembled on the hub 60, piston retracts and floor 101 drops downwardly after which the Geneva drive means 138 advances the hub chain 6 i to the hub stripper station where the chain 6 is held against vertical and lateral movement between the lower and upper chain guide bars 126, 126, respectively. While the hub 60 with the sheath 61 mounted thereon is thus held, a vertically movable marker-sealer means 129 is lowered into engagement with the hub-sheath assembly to seal and apply an identification mark thereto, and thereafter is moved out of engagement therewith.

Thereafter, the end surface of the hub is engaged by the lower and upper sheath and hub assembly stripper bars 120, respectively, and the assembly is forced from the hub mold core elements 5, as the hydraulic piston moves the stripper bars 120, 120' outwardly. The assembled sheaths and hubs then fall onto a conveyor means or into a container (not shown) and the chains 6 and 63 are advanced so that the next group of molded sheaths and hubs are assembled into the foregoing manner, as schematically shown in FIG. 13 of the drawing.

The mechanism for driving the several moving parts of the molding apparatus described herein is shown schematically in FIG. 8 of the drawing. The hub mold core endless conveyor chain 6 and the sheath mold core endless conveyor chain 63 are driven by motor 130 through a variable speed gear box 131 connected with the drive sprocket 132 which is mounted on shaft 133. The drive sprockets 136 and 137 fixedly mounted on shaft 133 impart a continuous motion to the chain 139 driving the Geneva gear means 138 and to the chain 3' driving the drive sprocket 3, respectively. The sprocket 3 rotates the loading wheel 4 and the sprocket 8 which drives chain 6. The gear box 131 and sprocket 132 also drive a plurality of timing cams 134 which actuate a plurality of microswitches which are operatively connected with the several electrical solenoid valves controlled by said switches. The hydraulic pressure required for operating the several hydraulic pistons is provided by a hydraulic pump 152 driven by a motor 151 which pumps oil from a reservoir 153 thru conduit 154 to the several soelnoid valve 155 controlling the fluid flow to the several pistons described herein. The motor through a flexible drive shaft connector drives the friction loader 9.

It will be apparent to those skilled in the art that whereas the specific embodiment illustrating the present invention relates to molding and assembling a plastic hypodermic needle hub and cannula with a sheath therefor, the present invention with obvious modifications can are in axial alignment with the molded be adapted to molding and assembling many other articles. Thus, the present application is not limited to apparatus for molding hypodermic needle hubs and sheaths or assembly thereof, but rather encompasses broadly the concept of molding a plastic material or a thermoplastic metal about a core element or other mold insert connected to a mechanical conveying means having the element or insert integral therewith or securely mounted thereon and wherein the molded part is allowed to remain on the mold element or insert and is conveyed to a second station where a second part is joined thereto either by mounting a formed part thereon as in the instant application or if desired, by using the first molded part still mounted on the core element or insert as a composite mold core element on which a second molding operation is performed to form a second part about the first part, as where an extension of the first molded part is desired or where an inlay or overlay of a different colored plastic is required. It will also be apparent to those skilled in the art that a wide variety of operations can be performed on the molded part or parts while held in a predetermined position or moved along a predetermined path, such as printing indicia thereon or sealing one part to another part after the assembly thereof.

Others may readily adapt the present invention for use under various conditions of service by employing one or more of the novel features disclosed or the equivalent thereof, without departing from the scope of the present invention as defined in the following claims.

I claim:

1. A method of molding and assembling comprising, molding a first part at a molding station on a mold core element integrally associated on a continuous conveyor means, conveying the molded part on said mold core element integrally associated with said conveyor means from said molding station and passing said conveyor means between guide means which restrain said conveyor means and mold core element against lateral movement, axially aligning a second part with that of the said conveyed molded part, and moving the said second part laterally into assembled engagement with said molded part while said molded part remains mounted on said mold'core element.

2. A method of molding and assembling comprising, molding a first part at a molding station on a mold core element integrally associated on a conveyor means, conveying the molded part on said mold core element integrally associated with said conveyor means from said molding station and passing said conveyor means between guide means which restrain said conveyor means and mold core element against transverse and vertical movement with respect to a predetermined plane in which said core element is disposed, axially aligning a second part with that of the said conveyed molded part, and moving one of said parts relative to the other of said parts into assembled engagement while said molded part remains mounted on said mold core element.

3. A method as in claim 1, wherein said mold core element supports a mold insert which is moldably joined to said first part at said molding station.

4. A method of molding and assembling a hypodermic needle sheath and hypodermic needle hub comprising, molding at a first molding station a hypodermic needle hub about a hypodermic needle cannula on a first mold core element which is integrally associated with a first continuous conveyor means, conveying said hypodermic needle hub on said mold core element from said first molding station and passing said conveyor means between guide means which restrains said conveyor means and said mold core element against lateral movement, molding at a second molding station a hypodermic needle sheath on a second mold core element which is integrally associated with a second continuous conveyor means, conveying said hypodermic needle sheath on said second mold core element from said second molding station and removing said sheath from said second mold core element, axially aligning said hypodermic needle sheath with said hypodermic needle hub and moving said hypodermic needle sheath laterally into assembled engagement with said hypodermic needle hub while said hub remains mounted on said first mold core element.

References Cited UNITED STATES PATENTS 2,593,668 4/1952 Gora 264-297 X 2,948,019 8/1960 Peterson 264297 X 3,013,308 12/1961 Armour 29451 CHARLIE T. MOON, Primary Examiner. 

1. A METHOD OF MOLDING AND ASSEMBLING COMPRISING, MOLDING A FIRST PART AT A MOLDING STATION ON A MOLD CORE ELEMENT INTEGRALLY ASSOCIATED ON A CONTINUOUS CONVEYOR MEANS, CONVEYING THE MOLDED PART ON SAID MOLD CORE ELEMENT INTEGRALLY ASSOCIATED WITH SAID CONVEYOR MEANS FROM SAID MOLDING STATION AND PASSING SAID CONVEYOR MEANS BETWEEN GUIDE MEANS WHICH RESTRAIN SAID CONVEYOR MEANS AND MOLD CORE ELEMENT AGAINST LATERAL MOVEMENT, AXIALLY ALIGNING A SECOND PART WITH THAT OF THE SAID CONVEYED 